Zelenskyy hails troops holding back Russian advance into eastern Ukraine

Ukraine President Volodymyr Zelenskyy said Russian must learn to regret its actions (Natacha Pisarenko/AP)

Ukrainian President Volodymyr Zelenskyy has said no-one knows how long the war in his country will last but his forces are defying expectations by preventing Russian troops from overrunning eastern Ukraine, where the fighting has been fiercest for weeks.

In his daily video address, Mr Zelenskyy said he is proud of the Ukrainian defenders managing to hold back the Russian advance in the Donbas region, which borders Russia and where Moscow-backed separatists have controlled much of the territory for eight years.